Dear Dan:
I used to work at many VARs. We were doing hot failovers on Linux, Unix, VMS, and even classic MVS/OS. When I was at a PBX manufacturer, we had failover in hot swappable cPCI boxes. You could put any cPCI card to sleep, even CPU cards, pull it, put a new cPCI card in and awaken it, all while the system was running. Just because a versionof such software WanSync can't do it under Linux, does not mean it can't be done. UNIX has had failover for years (ever since Real Time Reliable from AT&T (Western Electric (Now Lucent))).
Its real simple, the other system runs a BIOS looking at a watchdog timer. The running server resets that timer every few milliseconds. If the hot failover system BIOS sees that counter go to zero, it boots itself up and takes over. Yes it gets more complicated to deal with all possible scenarios, but it has been done for decades.
BTW, Linux kernel already supports virtual machines off of it. There is no need for VMWare, unless you need your hands held.
Pete |
